Folding press

ABSTRACT

A folding press, comprising at least two fixed beams: a first fixed beam (2 1 ) and a second fixed beam (2 2 ), to which are connected counterblades (5 1 , 5 2 ), and a ram beam (3) being disposed between these first fixed beam (2 1 ) and second fixed beam (2 2 ), and to the ram beam (3) being connected two thrust blades (6 1 , 6 2 ) on both parallel margins of the ram beam, whereby the counterblades and thrust blades constitute a first pair of folding blades (5 1 , 6 1 ) and a second pair of folding blades (5 2 , 6 2 ) while the ram beam (3) serves as joint ram for both pairs of folding blades. A force member (4) has been arranged to produce bidirectional working stroke of the ram beam (3) optionally toward the first or second fixed beam. A manipulation arm (7) is arranged to serve the first as well as the second pair of folding blades.

This application is a 371 of PCT/FI94/00409, filed Sep. 16, 1994.

The present invention concerns a folding press.

In prior arc a folding press As known comprising a frame fixedlysupported on the base; a fixed beam, which is fixedly connected to theframe; a ram beam, supported by the frame to be movable relative to thefixed beam; a force member, disposed between the ram beam and the framefor moving the ram beam relative to the fixed beam in order toaccomplish the folding work movement; a counterblade, attached to thefixed beam; a thrust blade, attached to the ram beam parallelly inrelation to the counterblade, the counterblade and thrust bladeconstituting a pair of folding blades between which a piece of metalsheet can be folded; a many-hinged manipulation arm for clamping andhandling the place which is to be folded, and for inserting it betweenthe folding blades in a pre-determined manner. In the folding press ofprior art the working stroke of the ram beam is usually vertical,whereby the throat between the blades is horizontal. Moreover,typically, a folding press of this type has only one pair of foldingblades, folding of the piece of sheet being performed in the gap thereofby handling the piece of sheet by means of a manipulation arm feeding itin between the folding blades.

The problem which the folding press of prior art is that only folds ofquite restricted kind can therewith be produced in the piece of sheetwith one single clamping, owing to the single thruster/counter-piecepair feature. If one desires further foldings of another kind in theworkplace, the manipulation arm must release the piece from its grip andthe piece has to be moved to be further folded on another folding press;this implies that the setting of the piece of sheet on the manipulationarm has to be redefined. this is cumbersome and time-consuming. Anotherproblem is that when the metal sheet is gripped by the clamping memberof the manipulation arm and transported in horizontal attitude into thefolding gap, the sheet will bend downward, giving rise to foldingerrors. Bending of the sheet during the manipulation step is alsoproblematic for the reason that when programming of the operation isaccomplished by means of computer-aided simulation, calculation of thesheet's bending is extremely difficult because air resistances etc. haveto be taken into account.

The object of the invention is to eliminate the drawbacks mentioned.

Specifically the object of the invention is to disclose a folding pressof completely novel type, which enables the building up of a versatilefolding press line as simply as possible and with few components.

The object of the invention is further to disclose a folding pressenabling with a single fixing of the sheet to the manipulation arm,folding of the sheet with two pairs of folding blades.

Further still, the object of the invention is to disclose a foldingpress enabling metal sheets to be folded without incurring substantiallyany bending of the sheets when they are being handled with themanipulation arm.

The folding press of the invention comprises a frame; a fixed beam,fixedly connected to the frame; a ram beam, supported by the frame to bemovable relative to the fixed beam; a force member, disposed between theram beam and the frame for moving the ram beam relative to the fixedbeam in order to accomplish the folding working stroke; an elongated andbeam-like counterblade, attached to the fixed beam; in elongated andbeam-like thrust blade, attached to the ram beam parallel relative tothe counterblade, the counterblade and thrust blade together forming afolding throat, or a pair of folding blades, the piece of metal sheetbeing foldable therebetween; and a many-hinged manipulation arm forclamping the piece to be folded and inserting it between the pair offolding blades in predetermined manner.

As taught by the invention, the folding press comprises at least twofixed beams, a first fixed beam and a second fixed beam, to whichcounterblades are connected, and the ram beam being disposed betweenthese first and second fixed beams and to the ram beam being connectedtwo thrust blades on both parallel margins of the ram beam, whereby thecounterblades and thrust blades define a first pair of folding bladesand a second pair of folding blades, the ram beam serving as joint ramto both pairs of folding blades. A force member is arranged to producebidirectional working stroke of the ram beam, optionally towards thefirst or second fixed beam. The manipulation arm is disposed to serveboth the first and the second pair of folding blades.

The invention affords the advantage that it enables a versatile foldingpress line in the simplest possible way and with few components.

The invention affords the advantage that after the piece to be foldedhas been grasped with the manipulation arm the piece of sheet materialcan first be folded with the first pair of folding blades by placing itwith the aid of the manipulation am between the blades in desiredpositions, while holding the piece firmly all the time, whereafter thefolding operation can be continued by transporting the piece of sheetmaterial with the manipulation arm into the gap of the second pair offolding blades, which is different from the first pair of foldingblades, and the folding operation can be continued with different bladeswithout need to release the hold of the manipulation arm on the piece.This is conducive to remarkably faster folding. It is possible with aso-called tandem folding press according to the invention, even in itssimplest form, to achieve the capacity of at least two folding presseswhile the initial and operating and service costs of the folding pressare quite much lower. The bi-directional motion of the ram bee can beachieved with a single force member, e.g., a hydraulic cylinder, andthis further notably simplifies the construction. It is equally possibleto provide several force members, as may be required.

In an advantageous embodiment of the folding press, the counterbladesand thrust blades are substantially vertical, the thrust blades beingdisposed on both parallel margins of the ram beam and the counterbladesbeing accordingly disposed on the vertical margins of the fixed beams,whereby the blades will define a first pair of folding blades and asecond pair of folding blades, both substantially vertical. The ram beamis guided to move substantially horizontally, and the force member isarranged to cause a horizontal working stroke of the ram beam. Byarranging the fixed and ram beams and the blades to be substantiallyvertical so that the folding throats are vertically oriented, thesignificant advantage is gained that the metal sheet can be handled invertical attitude, with the consequence that it keeps perfectly straightand will not bend, which could happen if the sheet were handled inhorizontal position. As the folding throats are vertical, horizontalworking stroke of the ram beam is naturally achieved, whereby oneobtains a maximally compact construction with minimal spacerequirements. At the same time, horizontal material flow of the workpieces is advantageously achieved.

In an advantageous embodiment of the folding press to the manipulationarm belongs a stand, relative to which the manipulation arm has beencarried to be rotatable, and the stand is affixed to the ram beam,advantageously at the centre of the ram beam. One achieves by locatingthe manipulation arm, e.g. a piece handling robot, in conjunction withthe ram beam that as the robot travels along with the ram beam itsmotion is exactly in the right direction because as the is being foldedthe clamping member of the robot moves away from the robot all the time.The ram beam is a firm fixing base for the robot, and the accuracy ofits positioning relative to the blades is well retained. It is a furtheradvantage that a centrally placed robot has the best chances to handlethe piece of sheet material just between and at the center of both fixedbeams. It is also an advantage that free floor space is left whereblanks going to be folded can be kept.

In an advantageous embodiment of the press the stand of the robot can beprovided with guides which are parallel to the blades and on support andin guidance of which the robot can be displaced. The travel length ofthe path can be nearly equal the length of the blades, wherebyadditional reach of the robot is gained. This is a particular advantageif the blade length is remarkable, e.g. 3 to 4 m.

In an advantageous embodiment of the folding press the manipulation armis an industrial robot, comprising a robot arm, supported on a stand,with a number of arms one after the other and hinged to each other and,on the outer end of this arm system, a clamping member for grasping thepiece of sheet material. Said industrial robot may be a standardindustrial robot, which commands a favourable price owing to it beingmanufactured in great numbers. The robot may equally be e.g. a robotprovided with a so-called serpentine robot arm.

In an advantageous embodiment of the folding press the folding presscomprises a tool storage for ram blades and counterblades. This toolstorage is disposed within reach of the manipulation arm so that the ramblades and counterblades can be changed with the aid of the manipulationarm.

In an advantageous embodiment of the folding press the tool storage is atool magazine, advantageously a revolving tool magazine, which has beenplaced on top of the folding press and in which the thrust blades andcounterblades are kept in positions substantially parallel to theirworking position which they have when mounted on the fixed and rambeams.

In an advantageous embodiment of the folding press the folding presscomprises a plurality of ram beams which have been disposedalternatingly between pairs of fixed beams and in line with these. Thefolding press comprises a plurality of manipulation arms, each one ofthem arranged to serve two pairs of folding blades and to forward thepieces being folded from one manipulation arm to the other. When therobots give pieces one to the other, they may on software level gothrough a so-called handshake procedure, i.e., if one robot grasps thepiece on the other side and the other robot releases its grasp theposition data of the piece is preserved all the time.

In an advantageous embodiment of the folding press the number ofmanipulation arms is equivalent to the number of ram beams.

In an advantageous embodiment of the folding press the folding press isdisposed in substantially horizontal position, the ram beam and fixedbeams with their folding blades substantially in a horizontal plane,whereby the piece of sheet material to be folded can be introducedbetween the pair of folding blades in substantially vertical position.The folding press may be disposed in horizontal position up at theceiling or on absolute floor level. The main thing is that the piece ofsheet material does not bend nor wobble since it can be handled invertical position. When a larger sheet with dimensions on the order ofe.g. 50×3000×14000 mm is being folded, the folding press may be disposedhorizontally on floor level, in which case also the height of the shophall in which the folding press has been mounted need not be exceedinglyhigh: a hall having a height on the order of 4 to 5 m will suffice. Ifthe folding press were mounted in vertical position as in the state ofart, a hall with height on the order of 7 m an least would be required.

In the following the invention is described in detail, referring to theattached drawing, wherein,

FIG. 1 presents schematically and in front view an embodiment of thefolding press of the invention;

FIG. 2 presents, viewed from above, the embodiment of FIG. 1;

FIG. 3 presents in elevational view the embodiment of FIG. 1;

FIG. 4 presents, viewed from the rear, the embodiment of FIG. 1; and

FIG. 5 presents schematically and in front view another embodiment ofthe folding press of the invention.

FIGS. 1-4 depict a folding press comprising a frame 1, which rests on abase. In this single frame 1 are assembled substantially all the partsand components of the folding press. The folding press comprises twofixed beams 2¹,2², which are called the first fixed beam 2¹ and thesecond fixed beam 2². The fixed beams 2¹ and 2² are fixedly connected tothe frame 1, in vertical position. Between these fixed beams, in oneplane with them, has been disposed a movable ram beam 3, which is guidedby the aid of guide members to be reciprocatingly movable relative tothe frame 1 and to the fixed beams 2¹,2².

The ram beam 3 is rectangular in shape and comprises two mutuallyparallel vertical sides. To these two vertical sides of the ram beam 3are connected thrust blades 6¹,6², which are elongated and beam-like. Asimilarly elongated and beam-like first counterblade 5¹ is connected tothat vertical side of the first fixed beam 2¹ which faces the verticalside of the ram beam 3 and the first thrust blade 6¹ thereto affixed. Alikewise elongated and beam-like second counterblade 5² is connected tothat vertical side of the first fixed beam 2¹ which faces the verticalside of the ram beam 3 and the second thrust blade 6² thereto affixed.In this way two pairs of folding blades are defined, a first pair offolding blades 5¹,6¹ and a second pair of folding blades 5²,6², thepiece of sheet metal being foldable in the throats between them. Thus,the ram beam 3 serves as joint ram to both pairs of folding blades. Thebidirectional horizontal working stroke of the ram beam 3, optionallytoward the first or second fixed beam 2¹ ; 2², has been accomplishedwith a force member 4, such as a hydraulic cylinder, which is disposedto act between the ram beam 3 and the frame 1. The number of forcemembers 4 may be selected in accordance with need in each instance, e.g.in accordance with the length of the ram bar 3. If for instance thelength of the ram bar 3 is e.g. 2.5 to 4.2 m, two hydraulic cylindersare needed, and if the length is greater than this, two or morecylinders are needed.

The folding press further comprises a many-hinged manipulation arm 7 forgrasping the piece of sheet material to be folded, introducing itbetween the first and/or second pair of folding blades in predeterminedmanner so that the manipulation arm 7 serves both the first and thesecond pair of folding blades. In FIG. 1 the manipulation arm has beendetached from its stand, while the manipulation arm can be seen in FIGS.2 ad 3. It is thus understood that the manipulation arm 7 comprises astand 8, relative to which the manipulation arm 7 has been rotatablycarried, and the stand 8 is centrally affixed to the ram beam 3. Themanipulation arm 7 is in this case an industrial robot, comprising arobot arm 9 supported by a stand 8 and comprising consecutive arms10,11,12 hinged to each other and a clamping member 13 for grasping thepiece of sheet material. The number of freedoms of the robot 7, i.e.,the number of its axles may, dependent on the state of advancement ofthe control, be such as is desired, advantageously not less than six,but it may for instance be unlimited employed is a robot provided with aso-called serpentine robot arm.

The folding press further comprises a tool storage 14, where various ramblades and couterblades 5¹,5² ; 6¹,6² can be kept ready to be exchangedand affixed to the ram and fixed beams. The tool storages 14 have beenschematically depicted in FIG. 1 only, not in any other figure. The toolstorages may be, as in the example of FIG. 1, revolving tool magazineswhich have been accommodated in the frame 1 on top of the folding pressand which contain thrust blades and counterblades 5,5¹,5² ; 6,6¹,6²stored in substantially parallel position in relation to their workingposition, or in this case the vertical position. The tool storages 14are, as shown in FIG. 1, arranged to be within reach of the manipulationarm 7 so that the ram blades and counterblades 5¹,5² ; 6¹,6¹ be changedwith the and of the manipulation arm 7. In the example of FIG. 1 thereare two tool storages 14, that is one for each pair of blades above eachpair of blades, so that the robot can be caused to drop the bladesdirectly from the magazine down into the blade fixing groove. If theblades are of the type which is assembled of mutually identical ordifferent bits, such blade bits can be dropped down into their fixinggrooves consecutively according to the so-called pearl string principle.The blade fixing groove and the corresponding groove or its like in thetool magazine are brought into register so that the fixing groove on thebeam (on the fixed or ram beam) in a way continues into the toolmagazine and one merely rotates into position from the tool magazinesuch a proper extension which holds the required blade and one lets theblade drop into the blade fixing groove. Blades can be selected from themagazine for mounting both on the ram beam and on the fixed beam. Theframe 1 comprises guide members 16, along which the tool magazine 14 canbe removed out of the vicinity of the pairs of blades from the workingarea to a piece where, for instance, the tool magazine will notinterfere with removal of the piece of sheet material from between theblades and away past their top ends.

In FIG. 5 is depicted a folding press comprising three fixed beam2¹,2²,2¹ and two ram beams 3. The ram beams 3 have been disposedalternatingly between the pairs of fixed beams 2¹,2² and in one linewith them. A folding press of this type can be formed by assembling inone frame two folding presses as in FIG. 1 and by affixing counterbladeson both vertical sides of the centremost fixed beam 2². The foldingpress comprises two industrial robots 7, each one arranged to serve twopairs of folding blades 5¹,6¹ ; 5²,6². Furthermore the robots 7 areadvantageously arranged to transport the piece of sheet material to eachother and also to shake hands on software level so that when one robottakes hold of the piece of sheet material on the other side and thefirst robot releases its hold of the piece of sheet material, thelocation data of the piece of sheet material is preserved all the timeand good accuracy is maintained. The machine may in this way operate asa versatile folding press line.

The invention is not exclusively delimited to concern the embodimentexamples presented in the foregoing: numerous modifications are feasiblewithin the scope of the inventive idea defined by the claims.

I claim:
 1. A folding press for folding a sheet of material comprising:aframe; at least two fixed beams fixedly connected to said frame, saidframe beams comprising a first and second fixed beam; at least twocounterblades, each counterblade connected to one of said fixed beams; amovable ram beam supported by said frame and disposed between said fixedbeams; a first and second thrust blade connected on parallel margins ofsaid ram beam; a force member producing a bidirectional working strokeof said ram beam optionally toward said first and second fixed beams,said counterblades and said thrust blades are substantially vertical,said thrust blades being disposed on both parallel vertical margins ofsaid ram beam and said counterblades being similarly disposed on thevertical margins of said fixed beams, said ram beam is movablesubstantially horizontally and said force member produces a horizontalworking stroke of said ram beam; and a manipulation arm serving saidfirst and second counterblades and said first and second thrust blades,wherein said first counterblades and said first thrust blade form afirst folding pair and said second counterblade and said second thrustblade form a second folding pair, said manipulation arm is adapted forgrasping said sheet of material and introducing said sheet of materialto said first folding pair and to said second folding pair, said sheetof material being received between said first counterblade and saidfirst thrust of said first folding pair and between said secondcounterblade and said second thrust blade of said second folding pair.2. The folding press according to claim 1 wherein said manipulation armcomprises a stand, the manipulation arm being rotatable relative to saidstand, and said stand is connected to said ram beam.
 3. The foldingpress of claim 2 wherein said stand is connected centrally to said rambeam.
 4. The folding press according to claim 1 wherein saidmanipulation arm is an industrial robot comprising a stand, a robot armformed of consecutive arms hinged to each other and a clamping memberfor grasping the piece of sheet material.
 5. The folding press accordingto claim 1 further comprising:a tool storage for storing said thrustblades and counterblades, wherein said tool storage is disposed withinreach of said manipulation arm so that said thrust blades and saidcounterblades are exchangeable by the aid of the manipulation arm. 6.The folding press according to claim 5 wherein said tool storage is atool magazine positioned on top of said folding press, said toolmagazine holding said thrust blades and said counterblades in asubstantially parallel position relative to their working position. 7.The folding press according to claim 1 further comprising a plurality ofsaid ram beams disposed between pairs of fixed beams and arranged inline with them;each one of said manipulation arms arranged to serve twopairs of said folding blades and to transport said folding blades to thepieces to be folded.
 8. A folding press for folding a sheet of materialcomprising:a frame; at least two fixed beams fixedly connected to saidframe, said frame beams comprising a first and second fixed beam; atleast two counterblades, each counterblade connected to one of saidfixed beams; a movable ram beam supported by said frame and disposedbetween said fixed beams; a first and second thrust blade connected onparallel margins of said ram beam; a force member producing abidirectional working stroke of said ram beam optionally toward saidfirst and second fixed beams, said counterblades and said thrust bladesare substantially vertical, said thrust blades being disposed on bothparallel vertical margins of said ram beam and said counterblades beingsimilarly disposed on the vertical margins of said fixed beams, said rambeam is movable substantially horizontally and said force memberproduces a horizontal working stroke of said ram beam; a manipulationarm serving said first and second counterblades and said first andsecond thrust blades; said first counterblades and said first thrustblade form a first folding pair and said second counterblade and saidsecond thrust blade form a second folding pair, said manipulation arm isadapted for grasping said sheet of material and introducing said sheetof material to said first folding pair and to said second folding pair,said sheet of material being received between said first counterbladeand said first thrust of said first folding pair and between said secondcounterblade and said second thrust blade of said second folding pair;and guides affixed to said ram beam in parallel relation to said foldingblades, wherein said manipulation arm is movable along said guides intovarious positions relative to said ram beams.
 9. A folding press forfolding a sheet of material comprising:a frame; at least two fixed beamsfixedly connected to said frame, said frame beams comprising a first andsecond fixed beam; at least two counterblades, each counterbladeconnected to one of said fixed beams; a movable ram beam supported bysaid frame and disposed between said fixed beams; a first and secondthrust blade connected on parallel margins of said ram beam; a forcemember producing a bidirectional working stroke of said ram beamoptionally toward said first and second fixed beams, said counterbladesand said thrust blades are substantially vertical, said thrust bladesbeing disposed on both parallel vertical margins of said ram beam andsaid counterblades being similarly disposed on the vertical margins ofsaid fixed beams, said ram beam is movable substantially horizontallyand said force member produces a horizontal working stroke of said rambeam; a manipulation arm serving said first and second counterblades andsaid first and second thrust blades; wherein said first counterbladesand said first thrust blade form a first folding pair and said secondcounterblade and said second thrust blade form a second folding pair,said manipulation arm is adapted for grasping said sheet of material andintroducing said sheet of material to said first folding pair and tosaid second folding pair, said sheet of material being received betweensaid first counterblade and said first thrust of said first folding pairand between said second counterblade and said second thrust blade ofsaid second folding pair; a tool storage for storing said thrust bladesand counterblades is disposed within reach of said manipulation arm sothat said thrust blades and said counterblades are exchangeable by theaid of the manipulation arm, said tool storage is a tool magazinepositioned on top of said folding press, said tool magazine holding saidthrust blades and said counterblades in a substantially parallelposition relative to their working position, wherein said tool magazinerevolves.
 10. A folding press for folding a sheet of materialcomprising:a frame; at least two fixed beams fixedly connected to saidframe, said frame beams comprising a first and second fixed beam; atleast two counterblades, each counterblade connected to one of saidfixed beams; a movable ram beam supported by said frame and disposedbetween said fixed beams; a first and second thrust blade connected onparallel margins of said ram beam; a force member producing abidirectional working stroke of said ram beam optionally toward saidfirst and second fixed beams, said counterblades and said thrust bladesare substantially vertical, said thrust blades being disposed on bothparallel vertical margins of said ram beam and said counterblades beingsimilarly disposed on the vertical margins of said fixed beams, said rambeam is movable substantially horizontally and said force memberproduces a horizontal working stroke of said ram beam; and amanipulation arm serving said first and second counterblades and saidfirst and second thrust blades; said first counterblades and said firstthrust blade form a first folding pair and said second counterblade andsaid second thrust blade form a second folding pair, said manipulationarm is adapted for grasping said sheet of material and introducing saidsheet of material to said first folding pair and to said second foldingpair, said sheet of material being received between said firstcounterblade and said first thrust of said first folding pair andbetween said second counterblade and said second thrust blade of saidsecond folding pair; and a plurality of manipulation arms, each one ofsaid manipulation arms arranged to serve two pairs of said foldingblades and to transport said folding blades to the material to befolded, wherein the number of said manipulation arms is equivalent tothe number of ram beams.
 11. A folding press for folding a sheet ofmaterial comprising:a frame; at least two fixed beams fixedly connectedto said frame, said frame beams comprising a first and second fixedbeam; at least two counterblades, each counterblade connected to one ofsaid fixed beams; a movable ram beam supported by said frame anddisposed between said fixed beams; a first and second thrust bladeconnected on parallel margins of said ram beam; a force member producinga bidirectional working stroke of said ram beam optionally toward saidfirst and second fixed beams, said counterblades and said thrust bladesare substantially horizontal, said thrust blades being disposed on bothparallel horizontal margins of said ram beam and said counterbladesbeing similarly disposed on the horizontal margins of said fixed beams,said ram beam is movable substantially horizontally and said forcemember produces a horizontal working stroke of said ram beam; amanipulation arm serving said first and second counterblades and saidfirst and second thrust blades; said first counterblades and said firstthrust blade form a first folding pair and said second counterblade andsaid second thrust blade form a second folding pair, said manipulationarm is adapted for grasping said sheet of material and introducing saidsheet of material to said first folding pair and to said second foldingpair, said sheet of material being received between said firstcounterblade and said first thrust of said first folding pair andbetween said second counterblade and said second thrust blade of saidsecond folding pair; wherein said folding press is disposed in asubstantially horizontal position, said ram beams, said fixed beams andsaid folding blades are disposed substantially in a horizontal plane andsaid sheet of material can be introduced between said folding blades ina substantially vertical position.